Stereoregularity of poly(2‐vinylpyridine) and poly‐(4‐vinylpyridine)

Abstract

AbstractIn order to determine the stereoregularity of poly(4‐vinylpyridine), 4‐vinylpyridine‐β,β‐d2 was synthesized from 4‐acetylpyridine. The 1H‐NMR spectra of the deuterated and nondeuterated polymers were measured and analyzed. From the 1H‐NMR spectra of poly(4‐vinylpyridine‐β,β‐d2), triad tacticity can be obtained, while the 1H‐NMR spectra of nondeuterated poly(4‐vinylpyridine) give the fraction of isotactic triad. The 13C‐NMR spectra of poly(4‐vinylpyridine) were also observed, and the spectra of C4 carbon of polymers were assigned by the pentad tacticities. The fraction of isotactic triad of poly(2‐vinylpyridine) and poly(4‐vinylpyridine) obtained under various polymerization conditions were determined. The radical polymerization and anionic polymerizations with phenylmagnesium bromide and n‐butyllithium as catalysts of 4‐vinylpyridine gave atactic polymers.